Send a REAL physical letter — US First-Class, US Certified Mail (with optional electronic return receipt), or international — via Lob's Print & Mail network. ACTION API, not a data lookup: paying causes a real letter to be printed and mailed. Flow: free quote -> paid send -> optional status/tracking poll. Pay-per-call via x402 on Base.
Quality grade
How grading works- ✓ Answers a real HTTP 402 challenge
- ✓ Publishes a /.well-known/x402 descriptor
- ✓ Payment address on record
- ✓ Settlement network declared
- ✓ Price declared
Paid endpoints
5 resource(s) advertised by this origin.
https://mailpulse.theaslangroupllc.com/api/health
Liveness check + current mode (test/live).
https://mailpulse.theaslangroupllc.com/api/verify-address
Deliverability check (US + international) via Lob address verification, before you pay to print.
https://mailpulse.theaslangroupllc.com/api/quote
Free, exact price quote + signed quote_id for a prospective letter. No Lob call, no charge.
https://mailpulse.theaslangroupllc.com/api/letters
THE action: prints and mails a real physical letter once payment settles. Requires a verified quote_id and a client_request_id for idempotency. Price varies $3.00-$14.00 by service; every order capped at $25.00.
https://mailpulse.theaslangroupllc.com/api/letters/{id}
Cheap status/USPS tracking poll for a previously sent letter.
How to call
curl -sS -i -X POST https://mailpulse.theaslangroupllc.com/api/verify-address # expect HTTP 402 Payment Required (about 0.01 USDC/call)Listed in
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